DESCRIPTION: (Applicant's Abstract) This application proposes a continuation of a Research Scientist Development Award to enhance skills for studying early onset of substance use, which has prognostic significance for substance abuse. In the current award period the activities were focused on a temperament model of vulnerability vs. resistance and this resulted in research, publications, and new grants. While the award facilitated the understanding of temperament dimensions, new questions were raised about self-regulation as a major predisposing factor for early onset. The overall aim for the continuation is to elaborate the significance of self-regulation concepts for etiology and prevention research, with a focus on obtaining a better understanding of activation and inhibition mechanisms. A program of skill development will include theoretical development through interaction with colleague-mentors and methodological development through ongoing consultation with the NIDA Methodology Center at Penn State. A second activity is conduct of collateral research in the context of ongoing grants; these will examine early onset in an African-American population, and examine activation and inhibition concepts in school-based designs and epigenetic research. Following from the first two aims, the third phase will use theory and findings on self-regulation constructs to develop self-control training modules for integration in a stepped preventive intervention for early-onset use; modules for use in a universal intervention and for use in a high-risk intervention will both be developed. These modules are designed to be integrated with other relevant program material so as to enhance the effectiveness of existing prevention approaches; this activity will lead to new research to test the effect of self-control training in a controlled trial.